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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to paging transmission systems and, more
particularly, but not by way of limitation, it relates to an improved
method of paging transmission which conveys text, coded matter and/or
pictorial data with maximum message content for reception and reproduction
by means of a paging-type receiver or equivalent functioning in
combination with a personal computer. In essence, the method entails the
initial development of the data as binary signal data with subsequent
encoding as, for example, ASCII data which is then transmitted via a
paging system and received for subsequent decoding and data output
indication.
2. Description of the Prior Art
There have been many prior attempts at collection and compression of data
for subsequent transmission to transmit maximum amounts of data in
compressed or bandwidth reduced form, with subsequent reception at remote
locations using receivers of limited size and data reproduction
capabilities. This has been particularly evident from the various attempts
at transmitting electrocardiogram (ECG) information for subsequent data
analysis and diagnosis. One such approach to the storage and transmission
of ECG data is disclosed in a paper entitled A New Data Compression
Algorithm for Computerized ECG Signal by Walter H. Chang and C. D. Kao
which appeared in IEEE/8th Annual Conference of the Engineering in
Medicine and Biology Society, pages 311-314, under copyright in 1986. This
paper is specifically related to transmission of ECG data and the method
of doing so utilizing signal compression using the Huffman Minimum Entropy
Coding Method to attain increased data reduction ratio. This method
succeeded in transmitting and retrieving ECG data of twelve leads per
patient along with a 30 second rhythm strip record and other pertinent
data; however, the system required a mass of storage medium and an
inordinate amount of time to deal with such a large amount of data, even
when reduced by data compression.
Current paging systems carry minimal information for reception and
indication at remote positions; however, this information carrying
capacity is extremely limited. Any attempt to transmit extensive data or
text messages by the present day national paging system hook-ups, i.e.,
EMBARK (Motorola) or SKYTEL (MTEL), would be cost prohibitive without
extensive alterations to the transmit/receive systems.
SUMMARY OF THE INVENTION
The present invention relates to improvements in coding and transmitting
message data for reception by a pager device having data storage and
downloading capability in combination with a digital computer. More
particularly, the device employs software controlling both transmission
and reception of data to enable reduction of complex, multifaceted
information to a transmittable data form with subsequent reception of the
data through a paging system receiver for intermittent download, decoding
and recomposition of the data through an associated computer. In essence,
data from a selected source is converted to binary code and then
translated into an alphanumeric code and, if the data message is of
sufficient length, the alphanumeric code data is divided into sequential
sub-files which are then presented to a paging switch in succession for
transmission. The transmitted data is received by a paging receiver with
sub-file storage, and the data is downloaded to an associated computer for
file reconstruction and subsequent alphanumeric code to binary translation
for reproduction of the data message information.
Therefore, it is an object of the present invention to provide a paging
transmission system that is capable of transmitting complex data to a
remote position for reception by a paging receiver to enable
reconstitution of the complex data for usage, observation, etc.
It is also an object of the present invention to provide an improved paging
transmission system that has large volume information capability.
It is yet further an object of the invention to provide novel computer
software for increasing the function and capability of existing pager
transmission hardware.
Finally, it is an object of the present invention to provide a relatively
simple and reliable paging transmission system that is capable of rapidly
transmitting various forms of data including medical data, digitized image
data, speech, radar indication, seismic data and actually any data that is
capable of being sensed and reduced to binary data form.
Other objects and advantages of the invention will be evident from the
following detailed description when read in conjunction with the
accompanying drawings which illustrate the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a broad function block diagram illustrating the crux of the
present invention;
FIG. 2 is a block diagram showing the transmitting portion of the paging
transmission system;
FIG. 3 is a block diagram showing the receiving portion of the paging
transmission system;
FIG. 4 is one form of paging receiver/palmtop computer that is suitable for
use in the present invention;
FIG. 5 illustrates one example of electrocardiograph data acquisition
system that is suitable for use with the present invention;
FIG. 6 is a program flow diagram for providing electrocardiograph data
acquisition for the present transmission system;
FIG. 7 is the program flow diagram succeeding FIG. 6;
FIG. 8 is the program flow diagram succeeding FIG. 7 and controlling final
data transmission;
FIG. 9 is a program flow diagram for the encode operation set forth within
the flow diagram of FIG. 8;
FIG. 10 is the flow diagram for the first part of the software for
receiving, decoding, displaying and analyzing received electrocardiograph
data;
FIG. 11 is a portion of flow diagram succeeding that of FIG. 10;
FIG. 12 is a third succeeding portion of flow diagram relating to the
receiving function; and
FIG. 13 is a flow diagram for the decode operation as set forth in FIG. 11.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates the basic paging transmission system 10 in its broad
process steps. The data source 12 may represent any form of real world
data that is measurable and susceptible of being embodied as a sequential
binary coded signal. While the paging transmission system 10 has been
specifically adapted to the transmission of ECG signals, as indicated by
the various drawing and flow chart designations; is should be understood
that data source 12 may produce any of various forms of message, i.e.,
text, pictorial or graphic data material and there is virtually no
limitation as to the type and length of subject matter. For example, some
benefits that business users may enjoy include the ability to receive
wireless information such as: (1) messages and electronic mail; (2) voice
mail notification; (3) data base information; (4) updates sent directly
into appointment and phone book files, worksheets, calendars, to-do lists
and memos; pictorial and graphic data; and (5) travel information
including flight data, car and hotel arrangements, etc.
The data source 12 provides output indication of its data content to a
stage 14 where the data, already in binary coded form, is translated into
a 7-bit ASCII code format (plus start and parity bits) that is compatible
with all standard forms of paging system. If the message length requires,
the 7-bit ASCII coded data may then be divided into sequential sub-files
in generation stage 16. The maximum size of the sub-files is only limited
by the storage capacity of the paging receiver, as will be further
described, and the number of sequential sub-files to be transmitted is
virtually unlimited.
The use of ASCII coded data is specified herein because that code is
provided for by the Telocator Alphanumeric Protocol (TAP) which has been
adopted as standard by the United States central paging terminal
manufacturers association for input of numeric, alphanumeric, or tone only
pages sent from a binary output device to a central paging terminal. Thus,
while ASCII is referred to in the specification and drawings, it should be
understood that other recognized five and seven unit codes (e.g., IBM
Transceiver Code, CCITT 5 Code, EBCDIC Code and others) may be substituted
with proper allowance in the system programming.
The successive sub-files from generation stage 16 are then transmitted via
modem and the standard Telocator Alphanumeric Protocol to the paging
switch for transmission at pager transmission stage 18. A single phone
line connection will place the sub-file data at the paging switch for
transmission. Thus, a single personal computer and appropriate software
converts binary data into 7-bit ASCII format, and divides into sub-files
if necessary, whereupon the data is transmitted via pager transmission 18.
A pager receiver then receives the data in ASCII format, with or without
sub-file sequence, via wireless transmission for subsequent pre-processing
and connection via RS-232 or other form of data connector interface to a
standard form of computer. In this case, a laptop or even more
miniaturized palmtop computer with adequate storage is desirable, and the
computer is programmed to carry out file reconstruction at stage 20
wherein all received and stored data sub-files are sequentially downloaded
to the computer and reordered into proper ASCII message format. At stage
22, the ASCII code or other code sequence is translated to a binary signal
sequence which is then conducted to output 24 for conversion to text,
voice, pictorial output, or other message embodiments.
This message sequence is carried out by the standard type of paging system
transmitter coupled with a computer that prepares the data through the
binary signal to ASCII code conversion with sub-filing sequence as the
software can control. Thereafter, the receiving pager is preferably one
having some portion of internal storage and which is connectable via
RS-232 or other data connector to a palmtop computer. As an example, the
receiver may consist of a Motorola NewsStream.TM. paging receiver coupled
with a Hewlett-Packard palmtop computer, Type HP95LX. While this paging
receiver/palmtop combination is especially desirable for use in the paging
transmission system 10, it is by no means indispensable because any of a
number of paging receivers and palmtop computers can be compatible for
functioning in accordance with the method of the present invention. A
teaching of the paging combination is the subject matter of U.S. Pat. No.
5,4043,721 in the name May.
Referring now to FIG. 2, the transmission portion of paging transmission
system 10 is illustrated in greater detail. A data acquisition system 26
functions to gather the basic data for conversion into binary code format
(either 8, 12, or 16-bit data) for input to a control computer 28 at the
transmitting station. The data measurement stage 30 may consist of some
form of data sensor and readout, along with a voice pickup 31 and image
scanner 33 or the like, which provides signal output to an analog to
digital converter 32 that provides digital output to an encoder 34.
Encoder 34 then translates the data to a binary code format which may be
output at connection 36 by either RS-232 hardline connection, wireless or
other line connection as input to computer 28. Optionally, measured data
permitting, encoder 34 may be bypassed with direct input of data on lead
38 either into data compression stage 40 or into ASCII II conversion stage
42. In either case, the data eventually gets converted to a prescribed
code format, e.g., ASCII, at stage 42 and, if necessary, the ASCII data is
divided down in divide stage 44 for storage as data sub-files in storage
46. Still another option is for the data to be initially received in ASCII
format from stage 47 and applied directly to divide stage 44.
Stored data sub-files 46 are then read out on line 48, and any identity
data is added at stage 50 as the data sequence is input to a standard
modem 52. The data message is then input via modem 52 to the paging switch
54 for subsequent transmission by transmitter 56 at the requisite paging
transmission system frequencies and modulation.
Referring to FIG. 3, the transmitted pager information is then received at
the pager receiver 58 as indicated at stage 60 and the data is downloaded
at stage 62 for input via connection 64 to a computer 66, for example the
Hewlett-Packard Type HP95LX palmtop computer. The connection 64 may be by
any of several modes, as will be further described, which are made
possible currently by using the Type HP95LX in combination with the
Motorola NewsStream.TM. data receiver. At present, the paging receiver
used is the Motorola Type A05KQC4373AA having a frequency range of 929-932
MHz and a total memory size of 32K bytes.
In palmtop computer 66, the data connection 64 applies downloaded ASCII
data and stage 68 functions to recombine the data sub-files into proper
sequence. Stage 70 then retranslates the data file from ASCII format to
binary signal data which is then compatible for output to any of data
display 72, printout 74, further processing 76 and/or audio output 75.
FIG. 4 shows a present form of compatible combination of pager/receiver 58
and palmtop personal computer 60. A special portability holder 80 is
formed with left and right channels 82 and 84, respectively, and these are
divided by a bar 86 which includes a release button 88 and feed through
connector type RS-232 (not shown). The Type HP95LX palmtop computer 66 is
lockable within channel 82 and the paging receiver 58 (NewsStream.TM.
type) is lockably received in channel 84 as a feed-through connector (not
shown) makes proper connection between the two units. The computer 66 and
paging receiver 58 are also releasible so that they may be separately
deployed, and the NewsStream.TM. paging receiver includes up to 32k of
storage so that it can receive and hold messages for subsequent engagement
in holder 80 to download its contents to the associated computer 66.
FIG. 5 illustrates the situation wherein the present paging transmission
system is employed for transmission of electrocardiogram (ECG)
information. Thus, a patient 90 is connected by a multiple of sensing
wires 92 (usually ten) for input to a standard type of ECG machine 94. The
ECG machine 94 includes a binary data conversion stage as well as a slot
96 for receiving a floppy disk such that previously recorded ECG
information may be conducted variously to an output computer 98. The
output from ECG machine 94 may be recorded on the floppy disk in slot 96
so that disk transfer function 100 will place the disk in computer 98 in
readiness for readout. Second, the ECG data may be directly applied by
wire connection 102 for input to the associated computer 98; or third, the
output from ECG machine 94 may be via phone line connection 104 to a modem
106 which transmits the ECG data via phone connection 108. The computer 98
then may further process the data to an ASCII form for connection through
a modem 52 and paging switch 54 (FIG. 2) whereupon the ECG data is
transmitted via wireless link.
The program controlling the unique function of the above-described hardware
is set forth in the following figures as will be described. The
description proceeds relative to use of the invention in an ECG
surveillance and reporting mode; however, it should be understood that the
paging transmission system will find use in very many modes of business
activity. FIG. 6 illustrates a start point in the paging transmission
system transmitter for the case wherein ECG data is to be processed. At
process start, the flow indicates initialization as variables, constants
and arrays are initialized at stage 110, the memory for ECG data is
allocated at stage 112 and the graphics system is initialized at stage
114.
Proceeding in FIG. 6, the flow steps bracketed by 116 all relate to initial
setup of the transmission station digital computer 28 (FIG. 2) for
receiving the ECG input data. Thus, lead selection alignment and x-axis
data allotment are created for each of the multiple leads of ECG data, in
the normal case twelve lead data. Flow stage 118 then functions to load
the raw ECG data into the computer memory and the raw data is filtered if
necessary in stage 120. If data quality permits, the filter stage 120 can
be bypassed via flow line 122 and processed through a next optional flow
stage 124 wherein the ECG data is decimated with consideration of the
sampling frequency. That is, the second optional stage 124 allows
pre-examination of the data and a choice to throw out certain redundant or
unnecessary data points thereby to reduce the overall data; or, flow stage
124 can also be bypassed with information on flow line 122 being applied
directly to the flow stage 126 to display the twelve lead ECG wave forms
on the data screen.
Program flow then proceeds to FIG. 7 and flow stage 128 which implements
scanning of the individual ECG data wave forms as a series of decision
stages are effected. Stage 130 queries as to whether or not the keyboard
is hit and if not the output is via flow line 132 back for recycle through
the scan operator command stage 128. If decision stage 130 shows
affirmative then flow proceeds to decision stage 134 which queries whether
or not the data is to be written to file. If affirmative, then the output
file for selected ECG data segment is readied at flow stage 136 and data
operation flow recycles on line 132 for scan of the next successive
operator command in flow stage 128. If the write to file question shows in
the negative, then flow proceeds to decision stage 138 to determine
whether or not there is a match between the selected ECG segment and the
arrow designators. If affirmative, flow proceeds to stage 140 and the
arrows align with a new segment of raw ECG data files. If negative, the
zoom operation is selected in stage 142 to display the respective lead
selection cursor and, when the lead is selected at decision stage 146, the
process stage 148 displays the selected lead of ECG data. Returning to
flow stage 140, when a new segment of raw ECG data is pointed, the flow
recycles to FIG. 6 and the input No. 2 to the flow stage 118 to load
additional raw ECG data into memory, which data relates to the new
segment. The new segment of data is then passed through the optional flow
stages 120 and 124 or in bypass on flow line 122 for display as one of the
multi-lead ECG wave forms on the screen at flow stage 126.
From flow stage 148 of FIG. 7, the operation proceeds to FIG. 8 and
interconnect No. 3 to a flow stage 150 which converts the selected ECG
data segments from binary to ASCII code data. The program for encoding the
selected ECG segment of stage 150 is shown in greater detail in FIG. 9.
Thus, the encode function starts with reading of the binary input file and
counting of the total number of bytes (N) at flow stage 152 and creation
of text output file at stage 154. The program initializes a pointer (X) at
a value of X=1 at stage 156. Flow stage 158 then reads the (X) to (X+2)
bytes of binary data from the binary input file.
Flow stage 160 then transfers the contents of the consecutive three binary
bytes into four ASCII bytes at byte positions (X) to (X+3) so that only
the least six bits of the ASCII bytes are occupied. In flow stage 162 the
function is to add 32 to every ASCII byte generated and in stage 164 the 4
resulting offset ASCII bytes are written to the text file. Flow stage 166
then sets N=N-3 and a decision stage 168 queries for correct data content.
If data content is correct then affirmative indication to end of file
stage 170 will proceed to close files stage 172. If, at decision stage
168, the N=0 query is negative, flow recycles via line 174 for reentry to
flow stage 158 after the value of X is incremented X=X+3 at stage 176. The
program then again transfers the contents of the next consecutive 3 binary
bytes into 4 ASCII bytes thereby occupying only the least six bits of the
ASCII bytes. When all multi-lead ECG data has been encoded, affirmative
output from end of file decision stage 172 effects closing of files at 174
to stop the encoding process.
The software for encoding (FIG. 9) and decoding (FIG. 13) the pager
transmission data is included herewith as:
Exhibit 1: PC Software; and
Exhibit 2: HP951x Software.
Returning again to FIG. 8, the flow stage 180 functions to split the
encoded ECG segment data in the form of ASCII code into messages that are
suitable for paging. That is, messages that have proper content for
sequential passage through the transmission system without overloading
receiver storage. A transmitted file may contain not only the twelve lead
ECG data but also important information as to the patient's age, sex,
blood pressure and other pertinent history. The total data file is
sub-divided into separate sub-files for transmission, the exact number and
size of the files to be determined by the program limits of the paging
system. Each of the sub-files contains some redundant information in order
to deal with inevitable transmission errors. For instance, the phone
number of the particular emergency room is sent in each sub-file and can
be reconstructed on an error-free basis even if all files are sent with
data corruption. This feature allows a receiving cardiologist to call the
sending emergency room to request a re-transmission of the ECG data, if
necessary. At flow stage 182, the paging transmission system is prepared
to transmit the ECG data. Then, in flow stage 184 the ECG messages are
each individually transmitted in sequence until end of transmission is
signified at flow stage 186.
The flow diagram of FIGS. 10, 11 and 12 illustrate the operation at the
paging receiver 58 and computer 66 (FIG. 3). In FIG. 10, the flow stages
within bracket 190 indicate initialization of variables and constants,
allocation of memory for received ECG data (a single file) and
initialization of the associated graphics system. The display graphics are
created in flow stage 192 as the twelve-lead ECG data can be selectively
presented and flow stage 194 sees to the X-axis data vector placement. The
computer screen is properly set up and formatted for twelve-lead data at
stage 196 and incoming messages are read at stage 198 for search at stage
200 to detect any incoming ECG data messages.
Referring to FIG. 11, the program proceeds to flow stage 202 wherein the
successive sub-file messages are joined to form the complete message, if
in fact more than a single sub-file was required. Thus, the ECG ASCII
message code files are formed into a single file. Thereafter, this single
file message is decoded in flow stage 204 as illustrated in FIG. 13. The
process of FIG. 13 is essentially the reverse of the encode routine of
FIG. 9. In FIG. 13, decoding commences with opening of an input file in
the text mode at flow stage 206, counting of the total number of bytes N,
and subsequent creation of a binary mode output file at stage 208. Any
header information is read and removed from the recombined ASCII file at
stage 210, and a data file pointer Y is initialized to Y=1 at stage 212.
Stage 214 effects reading the Y to Y+3 bytes of encoded data. Stage 216
sees a subtraction of a value of 32 from each ASCII offset byte thereby
creating new ASCII bytes.
In flow stage 218, three binary bytes are generated for every 4 ASCII bytes
that are read by increasing to eight the number of binary bits that are
occupied by the least significant six bits of ASCII bytes. Flow stage 218
writes the binary bytes to a binary file. Process stage 220 then sets
N=N-4 as flow proceeds to decision stage 222 to test for N=0. If negative,
flow recycles to flow stage 214 to process the next 4 bytes of data. If
decision stage 222 queries affirmative, then it proceeds to declare end of
file at stage 226 and the decoding process stops.
Referring again to FIG. 11 the decoded binary file data is loaded into ECG
data memory at flow stage 230, and flow stage 232 displays the 12-lead ECG
data on the computer screen. That is, the graphics screen 72 of the
portable computer 66 (see FIG. 3). The attendant operator may then select
an individual ECG lead for enlarged zoom display, an inherent and
necessary function for the diagnostics usage. The user's command from flow
stage 234 is decoded in flow stage 236 and flow stage 238 queries as to
whether or not to scan to the next lead. If affirmative, flow line 240
recycles to stage 236 to decode user's command, and if decision stage 238
is negative, then flow moves to decision stage 242 to pan the data to the
next time segment that relates to a selected lead. Upon decision, negative
response moves to interconnect No. 2 via flow line 244, and affirmative
response on flow line 246 effects panning to the next time segment at
stage 248 with recycle flow via line 250 to flow stage 236 and a wait for
decoding of user's command.
Referring to FIG. 12, flow line 244 proceeds to flow stage 252 to bring in
the ECG measurement screen, and flow stage 254 enables interactive display
of cursor movement on the ECG waveform in response to the user input
moving the cursor key 255. Flow stage 256 provides indication of cursor
location in time and amplitude subject to flow stage 258 and the
interactive second cursor 259 movement. ECG measurements in time and
amplitude are effected in flow stage 260 and recorded as at flow stage
262. Decision stage 264 then queries as to whether the process should end
and, if affirmative, it proceeds to stop.
If decision stage 264 tests negative, then process proceeds by flow line
266 to input interconnect No. 3 on FIG. 11. The recycle input from
interconnect No. 3 is to the flow stage 236 to wait for decoding user's
command. Thus, decision stage 238 selects a next ECG waveform or time
segment thereof for proc | | |
